Method of exchanging heat



H D. HILDEBRAND. 'METHOD OF EXCHANQLNG. HEAT.

APPLICATION FILED APIL 21,. 1 91.9.

Patented May18,1920.

INVENTOR HARRY 1). HILDEBRAND, or MOUNT VERNON, OHIO.

METHOD OF EXGHANGTN'G HEAT.

Specification of Letters Patent.

Patented May 18, 1920.

Original application filed January 2, 1917, Serial No. 140,093. Divided and this application filed April 21,

1919. Serial 'No. 291,425. a

T 0 all whom it may concern:

Be it known that I, HARRY D. HILDE- BRAND, residing at Mount Vernon, in the county of Knox and State of Ohio, a citizen of the United States, have invented or discovered certain new and useful Improvements in Methods of Exchanging Heat, of which improvements the following is specification. x I

In many of the arts, fluids, after being treated or after performing somefunctionor purpose, are in a highly heated condition and it is desirable to utilize the heat contained in such discharged fluid in raising the temperature of another quantity of fluid. This exchange of heat is effected by causing the two fluids to flow along'opposite sides of a conducting diaphragm, which will receive'heat from one of the fluids and transmit it to the other. I While not always necessary or desirable, it is usual to cause the two fluids to flow in opposite directions, thefluid to be heated entering the exchange system at or adjacent to the point of discharge of the other fluid from such system. While several conditions may affect the eificiency of a heat exchanger, the main condition is the relation of the areas of the surfaces of the fluids in contact with the transmitting diaphragm to the quantity of fluid flowing on opposite sides of the diaphragm at a given time, hence the greater the areas of the surfaces of the fluids in contact with the diaphragm, relative to the quantities of the fluids, the greater the velocity of heat exchange which may beimparted to the fluids through the exchanger.

The invention described herein has for its object the method of effecting an exchange of heat between two fluids by causing them to flow in their annular streams along opposite sides of a plurality of diaphragms formed of metal or other good conducting material, the respective fluids being caused to flow in progressively larger and smaller annular streams. It is a further object of the invention to prevent material loss of heat through radiation by causing the respective streams to alternate one with the other in such manner that the more highly heated fluid will flow between the annular streams of the cooler fluid. The invention is hereinafter more fully described and claimed.

In the acompanying drawings forming a part of this specification, Figure 1 is a side elevation of my improved heat exchanger;

Fig. 2 is an end View of the same, and Fig. 3 1s a transverse section of one of the elements of the exchanger. 7

lVhile other forms of apparatus may be employed in the practice of the method described and claimed herein, it is preferred to employ the construction described and claimed in'an application filed January 2nd, 1217 Serial Number 140,093, this application being a division thereof. As shown and described in said application, the preferred apparatus consists of two elements A and B which are formed by two series of pipes as a, b, 0, etc., and l, 2, 3, etc, of successively larger diameters, arranged one within the other, each succeeding outer section being made sufliciently shorter than the adjacent 1nner section to permit of connecting each section of one element with a corresponding section of the other element of the ex changer; Each succeeding section is hermetically secured to the inner adjacent section at its ends by any suitable means, preferably by welding. As hereinbefore stated, two elements constructed as above stated, form a part of the heat-exchanger and are connected together by transversely arranged pipes 11, as clearly shown in Figs. 1 and 2. One of the fluids, preferably the hot fluid, enters at one end of the inner pipe, as a, of

one element, as B, said pipe having its oppo-' of the pipe 0 of the element B. In like manner, the alternate pipes 0, e and g of the element B are connected to one end of pipes d f and 71- of the element A, and the opposite ends of these letter pipes d, f and g are con 'nected to pipes e, g and i of element B,

which has an outlet 70 for the cooled fluid.

, The fluid to be cooled enters through the inlet 12 of the pipe 1 which is the outermost pipe in series A and flows through a connecting pipe into pipe 2 of element B, the opposite end of the pipe 2 is connected to the pipe 3 of element A, which in turn is connected to pipe l of element B. In like manner the alternate pipes 6, 8, of element B have one end connected to pipes 7 and 9 of element A, and the opposite end of pipe 7 is connected to pipe 8 of element B, and the right hand end of pipe 9 of the element A in the diaphragm outlet for the oil which has been heated in passin through the system. In practice it is preferred that the apparatus emplo ed in the practice of the method shoulc be so constructed that due regard be had to frictional resistance,'the several streams of fluids being as thin as possible.

It is characteristic of the operation of this improved system that the highly heated oil will pass through alternate pipesof each element and be discharged from the outer pipe of one element, while the oil to be heated .enters the outer pipe of one of the elements and flows through pipes alternating with those through which the hot fluids pass and is finally discharged from one end of the inner pipe of one of the elements. It will be observed that as the cold fluid enters pipe 1, through inlet 12, it is outside of the pipe it, through which passes the comparatively cooled fluid and the fluid to be, heated passes to the pipe 2, which is surrounded by the pipe 1, which forms the last pass of the fluid to be cooled and has the outlet 70 for the discharge of the cooled fiuid.

As fluid to be heated flows along the several pipe sections,

it is gradually raised in temperature and the It will be understood that an element may consist of any desired number of sections but care should be taken to employ so many sections that ,there will not be so great a difference of temperature between the inner pipe section and the outer pipe section that rupture will result from differences of elongaemployed for the practice of the method, the

preferred form ofapparatus for the practice of the method being described and claimed in an application filed January 2, 1917, Serial Number 140,093.

I claim herein as my invention: I

l. The method of effecting an exchange of heat between fluids, which consists in causing the fluids to be cooled-to flow in progressively larger annular streams, and the fluid to be heated to flow in progressively smaller annular streams, which alternate with the streams of the fluid to be cooled. V

2. The method of effecting an exchange of heat between fluids which consists in causing a fluid of one temperature to flow in progressively larger annular streams and a fluid of another temperature to flow in progressively smaller annular streams which alternate with the streams of the first fluid.

In testimony whereof I have hereunto set my hand.

HARRY D. HILDEBRAND. 

